Carburetor for combustion engines and the like



Feb. 4, 1930. I E. SEIGNOL 1,745,957

CARBURETOR FOR COMBUSTION ENGINES AND THE LIKE I Filed Feb. 27, 1926 2 Sheets-Sheet 1 Fgb. 4, 1930. ,E. SEIGNOL CARBUBETOR FOR COMBUSTION ENGINES AND THE LIKE Filed Feb. 27. 1926 2 Sheets-Sheet 2 I Patented Feb. 1930 EDOUARD SEIGNOL,

PATENT Ori ice or PARIS, FRANCE GARBURETOR FOR COMBUSTION ENGINES AND THE LIKE Application filed February 27, 1926, Serial No. 91,222, and in France April 30, 1925.

This invention relates to a carburetor, more particularly applicable for use with internal combustion engines. 1

According to this invention there are combined (1) a Venturi serving as a diffuser, (2) a valve located on the air side of the diffuser Venturi neck, (3) a means for producing a very rich combustible mixture substantia 1y at the level ofthe fuel tank and capable of raising the liquid fuel insuch tank to the means which produces the very rich mixture, (4) a tube of large size leading into the diffuser a little on the engine side of the neck of the diffuser and leading in at this point the very rich mixture by the effect of the suction caused by the engine and the diffuser, and 5) a closed constant level tank connecting with the means for producing the rich mixture, a pi e connecting the constant level tank above t e fuel level therein to the diverging portion of the diffuser, and a fuel reservoir in communication with-the constant level tank.

Such arrangement has for effect to raise fuel from the reservoir to the constant level tank and'to ensure a differential working or automatic compensation of the carburetor whereby the difference in pressure between the constant'level tank and the means for raising the fuel to the mixture producing means is properly varied in accordance with the speed of the engine. j

In order to more clearly understand this invention, reference may be had tot-he accompanying drawings, wherein,

Fig. 1 is a diagrammatic view showing one embodiment of the invention, and

Fig. 2 is a similar view showing another embodiment of the invention.

As illustrated the carburetor comprises an ordinary diffuser a provided with a slidingvalve 7); d is a tube opening into the diffuser on the engine side of its neck a; tube d is of large diameter and is prolonged substantial- 1y to the level of the back tank 6 on the motor vehicle upon which the carburetor is placed. By tube of large diameter is here meant a tube sufficiently large to circus late a rich mixture of air and fuel, the quantity of fuel transported corresponding to the requirements of the engine. i

Tube (l terminates at its'other end in a primary Venturi tube f whose constriction is connected through a feed pipe with a closed constant level tank m, itsel in communication through a pipe n with the diffuser at a point situated on the engine side of the neck a and vthrough a pipe 0 with the back tank 6. This carburetor thus forms a differential or compensating carburetor, in which the main carbureting arrangement (element a, b, c, (1,) also provides the carburetion when running at reduced speed. The carburetor works as f0ll0ws':'

During normal running, the valve 7) being open,'the static fall in pressure acting on both tubes n and d is practically nil and the dynamic depression acting upon the endof tube d in the diffuser a is relatively high varying in relation to the speed of the air passing into the diffuser, the depression in the tube d being always higher than that in n. A strong suction therefore takes places in the Venturi tube f which is sufficient to suck the quantity of fuel required to produce a very rich mixture, transmit it through the tube d and to raise the fuel from the back tank 6 to the constant leveltank m. v

When running at reduced speed valve 1) is nearly closed, the static depression acting upon tube at increases but that acting upon the end of the tube d, which leads into the diffuser Venturi, is as large; the total fall in pressure is nevertheless increased by the increased dynamic effect at the discharge end of tube at due to the diverging clearance around the valve 6 and the effect of theVenturi tube f which have the effect of causing tube 9 to deliver fuel into the Venturi tube 7 in spite of the fall in pressure acting upon the level of liquid through tube a. The dynamic depression in this condition is maintained in d and g and is is substantially nil in n.

It will be seen that with such a carburetor, as the means both for running {at normal speed and at reduced speed only require-fuel to be raised up to the constant level tank m, the Venturi tube f may be placed as low down as desired. Even when the vehicle is running i on the air side of the constriction therein, a

fuel reservoir, a closed constant level tank situated substantially at the level of and in communication with said reservoir, means for drawing liquid from the constant level tank and producing a primary rich combustible mixture substantially at the level of said reservoir and, adapted to provide sufficient drop in pressure in said tank to raise l1qu1d fuel theremto from the reservoir, a

pipe of comparatively large diameter leading the rich mixture into the diffuser at a point slightly on the engine side of its constriction, and a tube of smaller diameter than said pipe closed to the atmosphere and connecting the constant level tank at a point above the fuel level with the diverging portion of the diffuser on the engines'ide.

2. In a carburetor, the combination with a diffuser venturi having fixed walls, of a valve on the air side of 'the constriction therein, a fuel reservoir, a closed constant level tankin communication with said reservoir, a pipe of comparatively large diameter leading from the diffuser at a point slightly on the engine side of its constriction and terminating in a Venturi tube. a pipe connecting the said Venturi tube with the liquid fuel in the constant level tank, and a tube of smaller diameter than said first-named pipe closed to the atmosphere and connecting theconstaut level tank at a point above the fuel level with the diverging portion of the diffuser on the engine side.

3. In a carburetor, the combination with a diffuser venturi having fixed walls, of a valve on the air side of the constriction therein, a fuel reservoir, a closed constant level tank the bottom of which is situated slightly above said reservoir, a conduit connecting the bottom of said reservoir with a point in the constant level tank above the level of the fuel therein, a pipe of comparatively large diameter terminating at one end at a point in the diffuser slightly on the engine side of the constriction therein, a Venturi tube situated in proximity to the top of the constant level tank and in communication with said pipe, a pipe connecting the constriction of said Venturi tube with the liquid fuel in the constant level tank, and a tube of smaller diameter than said first-named pipe closed to the atmosphere and one end of which connects with the constant level tank at a point above the level of the fuel therein while the other end connects with the difiuser at a point c nsiderably on the engine side of the constriction therein relative to the tube of comparatively large diameter.

4. In a carburetor, the combination with a diffuser venturi having fixed walls of a valve on the air side ofthe constriction therein, a fuel reservoir, a closed constant level tank fixed on the fuel reservoir, a conduit connecting the bottom of said reservoir with a point in the constant level tank above the level of the fuel therein, a pipe of comparatively large diameter terminating at one end at a point in the diffuser slightly on the engine side of the constriction therein, a Venturi tube situated in proximity to the top of the constant level tank and in communication with said pipe, a pipe connecting the constric tion of said Venturi tube with the liquid fuel in the constant level tank, and a tube of smaller diameter than said first-named pipe closed to the atmosphere and one end of which connects with the constant level tank at a point above the level of the fuel therein while the other end connects with the diffuser at a point considerably on the engine side of the constriction therein relative to the tube of comparatively large diameter.

5. In a carburetor, the combination with a diffuser venturi having fixed walls of a closed constant level tank mounted on said fuel reservoir, a conduit connectin the bottom of said reservoir with a point in the constant level tank above the level of the fuel therein, a straight pipe of comparatively large diameter terminating at one end at a point in the diffuser slightly on the engine side of the constriction therein, a valve slidably mounted on the pipe at the air side of said constriction,

a Venturi tube connected with said pipe and disposed above the level of the fuel in the constant level tank, a pipe connecting the constriction of said Venturi tube with the liquid fuel in the constant level tank,-and a tube of smaller diameter than said first-named pipe closed to the atmosphere and one end of which connects with the constant level tank at a point above the level of the fuel therein while the other end connects with the diffuser at a. point considerably on the engine side of the constriction therein relative to the tube of comparatively large diameter.

6. In a carburetor system the combination with a fuel reservoir and a closed constant level tank, of a primary venturi, a feed pipe communicating at one end with the constant level tank below the fuel level and at the other end with the restriction insaid primary venturi, a rigid wall diffuser venturi, a rich mix-.

ture pipe of-relatively large diameter connecting the primary venturi with the diffuser and entering the difluser in the form of a. straight .pipe of uniform diameter terminating at a point slightly on the engine side of the constriction in said diffuser, a conical valve slidably mounted on said rich mixture pipe on the air side of the diffuser and having a taper substantially the same as but slightly more abru t than that of the convergent part of the di user venturi so that when partly closed the speed of the current of airpast the, open discharge end of the rich mixture tube will be increased with consequent increase of the dynamic effect, and a suction pipe co'n-r necting the constant level tank at a point above the fuel level with the diverging portion of the difi'user.

In testimony whereof I have aflixed m signature.

v EDOUARD SEIGNOL. 

